Volume 2 Supplement 1

ESICM LIVES 2014

Open Access

0990. Role of amplitude and rate of deformation in ventilator-induced lung injury

  • A Protti1,
  • DT Andreis2,
  • M Milesi2,
  • P Pugni2,
  • F Nicosia2,
  • T Maraffi2,
  • V Melis2,
  • M Monti2,
  • E Votta3 and
  • L Gattinoni1, 2
Intensive Care Medicine Experimental20142(Suppl 1):P75

DOI: 10.1186/2197-425X-2-S1-P75

Published: 26 September 2014

Introduction

Increasing both Tidal Volume (VT) (amplitude of lung deformation) and Inspiratory Flow (V') (rate of lung deformation) augments incidence of Ventilator-Induced Lung Injury (VILI) [1].

Objectives

To clarify whether increasing V' at constant VT augments incidence of VILI.

Methods

Twenty-eight healthy piglets were mechanically ventilated for up to 54 hours. Each animal was assigned to one of three groups of VT (300-400 ml; 500-600 ml; 750 ml) and one of two groups of V'. Lower and higher V' were obtained by setting inspiratory-to-expiratory time ratio as high as 1:2 or as low as 1:9. Respiratory rate was always 15 breaths per minute. Interplay between VT and V' was assessed at the beginning of the study as airway pressure-volume loop area (or dynamic respiratory system hysteresis). VILI was defined as pulmonary oedema (lung weight gain ≥10% across the study period).

Results

Main findings are reported in Table 1.
Table 1

Inspiratory flow and incidence of VILI

 

VT 300-400 ml

VT 500-600 ml

VT 750 ml

 

Lower V´

Higher V´

Lower V´

Higher V´

Lower V´

Higher V´

Tidal volume (ml)

338±48

335±42

530±27

520±27

750±0

750±0

Inspiratory flow (ml/sec)

272±36

838±105*

398±21

1278±38*

600±84

1242±95*

Hysteresis (ml*cmH2O)

6260±2236

12938±3356*

11101±4508

34126±4508*

18415±3520

46915±7954*

Incidence of VILI

0/4

1/5

0/5

4/5*

2/5

4/4

Data are presented as mean±standard deviation. * p< 0.05 vs. Lower V' within the same VT group (Student's t, Mann-Whitney Rank Sum or Fisher's exact tests). Hysteresis was associated with incidence of VILI (R=0.68, p< 0.0001) (Spearman Rank Order Correlation).

Conclusions

Increasing V' (rate of lung deformation) while maintaining VT (amplitude of lung deformation) constant augments incidence of VILI. Further studies are needed to clarify whether dynamic respiratory system hysteresis is an independent predictor of VILI.

Declarations

Grant acknowledgment

This study was supported in part by an Italian grant provided by Fondazione Fiera di Milano for Translational and Competitive Research (2007, Luciano Gattinoni) and by GE Healthcare.

Authors’ Affiliations

(1)
Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico
(2)
Università degli Studi di Milano
(3)
Politecnico di Milano

References

  1. Protti A, et al.: Lung stress and strain during mechanical ventilation: any safe threshold? Am J Respir Crit Care Med 2011, 183: 1354–1362. 10.1164/rccm.201010-1757OCPubMedView ArticleGoogle Scholar

Copyright

© Protti et al; licensee Springer. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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